Extracorporeal blood pumps or in vivo heart assist devices comprise various designs, including peristaltic roller pump, centrifugal pumps, axial flow pumps, pneumatic chamber pumps, and hydraulic chamber pumps. These pumps vary widely in cost and efficacy, and their uses vary from supporting a patient on a heart/lung machine to assisting the human heart as a bridge to transplant or replacing the human heart.
One such application is long term Extracorporeal Membrane Oxygenator (ECMO) support. In this process, a heart/lung machine provides cardiopulmonary support to a patient, typically a pediatric patient, for many days. Many technical challenges are faced in providing such support. The patient is maintained in an unconscious state. Fluids must be provided to the patient via intravenous (IV) administration to sustain circulation and systemic pressure. This is a critical process, and inattentiveness by medical personnel can have serious negative consequences.
With current pumps, inadequate input volume can result in excessive negative pressures in the pump inlet conduit and the patient's venous system, which may result in air emboli entering the extracorporeal circuit via the cannulation site.
Therefore, it would be desirable to have an adaptive pump mechanism that can adjust its stroke volume and stroke rate to maintain a fluid flow rate that supports a specified blood pressure range within a patient.